That leads to a question, since "one line" can be interpreted as one complete sentence OR one musical phrase - which can be totally different. IF we take the "complete sentence" for that "one line" then I offer this:
"And the rocket's red glare, the bombs bursting in air, gave proof through the night that our flag was still there." - USA: National anthem a.k.a. "The Star-Spangled Banner"
BUT if we are in a different mood,
"Who will climb the stair to try, who will sample my supply" - Cole Porter's "Love for sale."
OR if we are going for absolute, laser-like purity of focus, there is this Neal Hefti composition from a TV theme of a few decades ago...
"da da da da da da da da da da da da Batman"
You KNOW I can't do this without a touch of the whimsical.